HEAT!!!The Australian Experience

Professor Will SteffenClimate Councillor

Outline of Talk

1. Extreme heat and heatwaves in Australia

2. Consequences for Australians

3. Future heat: risks and responses

Trend in annual average temperature

Source: Bureau of Meteorology 2015

Averages and extremes

Based on IPCC 2007Adapted from IPCC 2007

Hot weather is increasing

Continental-scale heatwave

Source: Bureau of Meteorology

Heatwaves

Heatwaves are becoming more intense, lastinglonger and occurring more often. More frequent and hotter days are projected for the future. CSIRO and BoM 2015

2013: Australia’s Hottest Year on RecordVirtually Impossible without Climate Change

Source: Knutson et al. 2014

Bushfires

10

High Fire Danger Weather

Sources: Clark et al. 2013; Jones et al. 2013

MELBOURNE AREA

11

Bushfires and Climate Change

• Climate change makes bushfire conditions worse by increasing the frequency of very hot days.

• Between 1973 and 2010 the Forest Fire Danger Index increased significantly at 16 of 38 weather stations across Australia, mostly in the southeast. None of the stations showed a significant decrease.

• Projected increases in hot days across Australia, and in dry conditions in the southwest and southeast, will very likely lead to more days with extreme fire danger in those regions.

Source: Vic DHS 2009

Melbourne 2009 heatwave

Extreme heat and health

• Extreme heat causes more deaths than any other natural hazard in Australia.

• Recorded deaths from specific extreme heat events:374 excess deaths, Melbourne, Jan-Feb 200923% increase in deaths, Brisbane, Feb 2004110 excess deaths, Sydney, Jan 1994

• Without adaptation, heatwaves projected to cause over 400 excess deaths per year by 2050 in Victoria along (a southern Australian state).

Sources: DHS 2009; Tong et al. 2010; Gosling et al. 2007; Keating and Handmer 2013

Extreme heat and worker productivity

• Extreme heat in 2013/2014 drove an annual economic burden of nearly $8 billion via worker productivity losses

• Heat stress in northern Australia has reduced labour capacity by 10% in past few decades; further 10% drop projected by 2050

• Loss of worker productivity globally due to heat stress projected to be as high as USD 1 trillion by 2030.

Sources: Zander et al. 2015; Dunne et al. 2013; Kjellstrom and McMichael 2013

Heatwaves and infrastructure

Infrastructure damage from the 2009 Melbourne heatwave

• An estimated 500,000 residents were without electricity on evening of 30 Jan.

• Extensive damage to railways:29 cases of rail tracks bucklingElectrical faults in signalingFailure of air-conditioning in more than 50% of trains

Extreme heat and natural ecosystems

• Marine heatwaves have caused repeated coral bleaching of the Great Barrier Reef since the late 1970s.

• Heatwaves combined with extended drought have caused mass mortality in koalas.

• Since 1994, more than 30,000 flying foxes have died in extreme heat. On 12 Jan 2012, over 3,500 were killed along the NSW coast when temperatures exceeded 42oC.

• In Jan 2010 in Western Australia, over 200 of the endangered Carnoby’s black cockatoos were killed when temperatures rose to 48oC.

Sources: Saunders et al. 2011; Welbergen et al. 2008; Gordon et al. 1998

CSIRO and BoM 2015

More heat to come

Stabilising the climate system

Meinshausen et al. 2009

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